Projection device

Abstract

The invention discloses projection equipment, and relates to the technical field of display. According to the invention, one super-structure lens is used for replacing a plurality of traditional optical lenses to realize a focusing function, and the product size can be reduced. The polarization direction of the light is adjusted through the polarization adjusting element, so that different light entering the super-structure lens has different polarization directions, and the super-structure lens can focus the light with different polarization directions on different radial positions corresponding to the positions of different pixel subunits of the pixel units of the liquid crystal element; therefore, the use of color filter elements can be reduced to improve brightness.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a projection device. Background Art

[0002] Lens is a basic optical element, which is made according to the law of light refraction and is widely used in the field of optoelectronic technology, such as cameras, projectors, microscopes, etc. In traditional projection equipment, multiple lenses are usually stacked together to achieve functions such as shaping and focusing.

[0003] At present, projectors are widely used in various situations, such as office briefings, film and television playback, installation art, etc. Most projectors are based on spatial light modulators (SLM), which mainly include transmissive LCD (Liquid Crystal Display) projection, reflective LCoS (Liquid Crystal on Silicon) projection and reflective DMD (Digital Micro-Mirror Device) projection. In recent years, LCD projection has been widely used due to its low price. However, the LCD architecture usually uses color filter elements for color adjustment, which will bring about the problem of brightness loss. Summary of the invention

[0004] In view of this, the present invention provides a projection system which can reduce the volume of the product and reduce light loss.

[0005] In a first aspect, the present invention provides a projection device, comprising:

[0006] A light source device, for generating light source light, wherein the light source light includes a first light and a second light;

[0007] A first liquid crystal panel, used for modulating the light from the light source, wherein each pixel unit of the first liquid crystal panel includes a first pixel sub-unit and a second pixel sub-unit, wherein the first pixel sub-unit is used for processing the first light, and the second pixel sub-unit is used for processing the second light;

[0008] a polarization adjustment element, located at the light output side of the light source device, and used to adjust the polarization direction of the light source light so that the first light has a first polarization direction and the second light has a second polarization direction, wherein the first polarization direction and the second polarization direction are different;

[0009] The meta-lens is located between the polarization adjustment element and the first liquid crystal panel, and is used to guide the first light to be incident on a first pixel subunit of the first liquid crystal panel, and guide the second light to be incident on a second pixel subunit of the first liquid crystal panel.

[0010] In a possible implementation, the light source light further includes a third light;

[0011] Each pixel unit of the first liquid crystal panel further includes a third pixel sub-unit, and the third pixel sub-unit is used to process the third light;

[0012] The polarization adjustment element is further used to make the third light have a third polarization direction, and the third polarization direction is different from the polarization directions of the first polarization direction and the second polarization direction;

[0013] The meta-lens is further used to guide the third light to be incident on a third pixel subunit of the first liquid crystal panel.

[0014] In a possible implementation manner, the light source light further includes a fourth light, and the projection device further includes:

[0015] A second liquid crystal panel, each pixel unit of the second liquid crystal panel includes a fourth pixel sub-unit, and the fourth pixel sub-unit is used to process the fourth light.

[0016] In a possible implementation, the polarization angle of light incident on the metalens satisfies the following conditions:

[0017]

[0018] in, represents the polarization angle, λi represents the wavelength of the incident light, d represents the distance between the meta-lens and the first liquid crystal panel, and Δr represents the center distance between adjacent pixel sub-units of each pixel unit in the first liquid crystal panel.

[0019] A possible implementation also includes:

[0020] The polarization control device is located between the light source device and the polarization adjustment element, and is used to control the polarization direction of the light from the light source so that the polarization directions of all lights in the light from the light source are consistent.

[0021] In a possible implementation manner, the light source device generates the first light, the second light, and the third light in a time sequence.

[0022] In a possible implementation, the first liquid crystal panel displays color field images of the first light, the second light, and the third light of the input signal in time sequence.

[0023] In a possible implementation, the first liquid crystal panel is a black and white screen.

[0024] In a possible implementation manner, the first pixel sub-unit and the second pixel sub-unit have the same size.

[0025] In a possible implementation manner, the first pixel sub-unit, the second pixel sub-unit, and the third pixel sub-unit have the same size.

[0026] The present invention uses a meta-lens to replace multiple traditional optical lenses to achieve the focusing function, which can reduce the volume of the product. The polarization direction of light is adjusted by the polarization adjustment element, so that different lights incident on the meta-lens have different polarization directions. The meta-lens can focus light with different polarization directions on different radial positions, corresponding to the positions of different pixel sub-units of the pixel unit of the liquid crystal element, thereby reducing the use of color filter elements to improve brightness. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a functional module schematic diagram of an existing projection device;

[0028] Figure 2 It is a structural schematic diagram of an existing projection device;

[0029] Figure 3 A schematic diagram of the structure of a projection device provided by an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of the structure of a meta-lens provided in an embodiment of the present invention;

[0031] Figure 5 A schematic diagram of the structure of a projection device provided by an embodiment of the present invention;

[0032] Figure 6 A schematic structural diagram of a projection device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to make those skilled in the art better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Although the disclosure in the present invention is introduced according to one or several exemplary examples, it should be understood that each aspect of these disclosures can also constitute a complete technical solution separately. In the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0034] In the present invention, in order to facilitate the clear description of the technical solutions of the embodiments of the present invention, the words "first", "second" and the like are used to distinguish the same items or similar items with basically the same functions and effects. Those skilled in the art can understand that the words "first", "second" and the like do not limit the quantity and execution order, and are only used to illustrate and distinguish the objects to be described. There is no order distinction, nor does it represent a special limitation on the number of devices or messages in the embodiments of the present invention, and cannot constitute any limitation on the embodiments of the present invention. "Multiple" means two or more, and similar words such as "include" or "comprising" mean that the element or object appearing before the word covers the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0035] In order to fully understand the present invention, a detailed description will be provided below to illustrate the technical solution of the present invention. Preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other embodiments.

[0036] Figure 1 Schematic diagram of functional modules of a projection device provided by an embodiment of the present invention. Figure 1 As shown, the projection device includes an image processor 101 and a projection optical engine 102. Among them:

[0037] The image processor 101 may be a microcontroller, a dedicated image processing chip, etc. The microcontroller may be an ARM chip, a microcontroller unit (MCU), etc. The dedicated image processing chip may be an image signal processor (ISP), a graphics processing unit (GPU), an embedded neural network processor (NPU), etc. The image processor 101 may be used for video decoding, image quality processing, etc.

[0038] The projection optical machine 102 may include a driver chip, a spatial light modulator, and a light source. The light source may include a laser light source, an LED light source, a fluorescent light source, etc. The spatial light modulator may be a digital micromirror device (DMD), a liquid crystal display (LCD), a liquid crystal on silicon (LCOS), etc., which is used to modulate the light source to generate image light. The driver chip corresponds to the spatial light modulator, for example, the digital micromirror device may be driven by a digital light processing element (DLP). The projection optical machine 102 is used to project the image to be projected into a projection screen.

[0039] In some embodiments, the projection device further includes a central controller 103 with one or more processing cores, which may be a CPU, ARM, MCU or other controller. The central controller 103 is the control center of the projection device, and uses various interfaces and lines to connect various parts of the entire projection device, and can run or execute software programs and / or operating systems stored in the storage module 104, and call data stored in the storage module 104. Optionally, the image processor 101 and the central controller 103 may be integrated into one processor.

[0040] In some embodiments, the projection device further includes a storage module 104 of one or more computer-readable storage media, an input module 105, a communication module 106, a power supply 107 and other components. Those skilled in the art will appreciate that Figure 1 The structure of the projection device shown in the figure does not constitute a limitation on the projection device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0041] The storage module 104 can be used to store software programs and operating systems. The central controller 103 executes various functional applications and data processing by running the software programs and operating systems stored in the storage module 104. The storage module 104 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the projection device, etc. In addition, the storage module 104 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage devices. Accordingly, the storage module 104 can also include a memory controller to provide the central controller 103 with access to the storage module 104.

[0042] The projection device may further include an input module 105, which may be used to receive input digital or character information and generate remote control, keyboard, mouse, joystick, optical or trackball signal input related to user settings and function control.

[0043] The projection device may further include a communication module 106. In some embodiments, the communication module 106 may include a wireless module. The projection device may perform short-distance wireless transmission through the wireless module of the communication module 106, thereby providing the user with wireless broadband Internet access. For example, the communication module 106 may be used to help the user access streaming media, etc.

[0044] The projection device further includes a power supply 107 for supplying power to various components. In some embodiments, the power supply 107 can be logically connected to the central controller 103 through a power management system, so as to manage charging, discharging, and power consumption through the power management system. The power supply 107 can also include any components such as one or more DC or AC power supplies, recharging systems, power failure detection circuits, power converters or inverters, and power status indicators.

[0045] Figure 2 A schematic diagram of the structure of a projection device provided by an embodiment of the present invention. Figure 2 As shown, the projection device includes a light source device 201, a light homogenizing element 202, an illumination system 203, a display chip 204, and an imaging system 205. The light source light generated by the light source device 201 is homogenized by the light homogenizing element 202, and the illumination system 203 images the light spot of the exit surface of the light homogenizing element 202 on the display chip 204. The display chip 204 modulates the incident light source light into image light and irradiates it into the imaging system 205, and finally images the image light onto a projection object such as a screen to form a projection picture. Among them, the display chip 204 can be any one of DMD, LCOS, and LCD; the imaging system 205 is generally a lens system, such as a projection lens.

[0046] In addition, the projection device may also include a light source control module (not shown in the figure), which can control the operation of one or more light sources in the light source device 201, so that the light source device 201 emits light of a specified wavelength band required for generating an image. Further, the light source device 201, the light homogenizing element 202, the illumination system 203, the display chip 204 and the imaging system 205 may all be included in the projection optical machine 102 (refer to Figure 1 )middle.

[0047] The light source device 201 may include one or more light sources. The light source may be a laser light source, an LED light source, or a fluorescent light source, etc. Further, the light source may be a single light emitting element or a light emitting element array, and the light emitting element array may include light emitting elements of different colors. For example, the light source may be an LD light source or an LED light source that generates blue light, green light, or red light, etc., or the light source may be a multicolor laser, i.e., a light emitting element array that includes multiple lasers, such as a light source that includes a blue laser and a red laser, or includes a blue laser and a green laser, or includes a blue laser, a red laser, and a green laser at the same time.

[0048] The light homogenizing element 202 is used to homogenize the light source light generated by the light source device 201. Specifically, the light homogenizing element 202 includes an incident surface and an exit surface, and the light homogenizing element 202 is used to homogenize the light source light incident from its incident surface, so as to form a light spot having the same shape as the display chip on its exit surface, such as a light spot in a rectangular, circular, etc. shape. For example, the light homogenizing element 202 can be a light rod, a compound eye, etc.

[0049] The illumination system 203 is a part from the light homogenizing element to the display chip, and is used to image the light spot on the exit surface of the light homogenizing element 202 onto the display chip 204. By way of example, the illumination system 203 may include one or more lenses.

[0050] Figure 3 A schematic diagram of the structure of a projection device provided by an embodiment of the present invention. Figure 3 As shown, the projection device includes a light source device 301, a meta-lens 302, a liquid crystal panel 303 and a projection lens 304. The outgoing light of the light source device 301 is guided to the liquid crystal panel 303 through the meta-lens 302. The liquid crystal panel 303 irradiates its incident light into the projection lens 304, and finally images the image light onto the projection screen.

[0051] The light source device 301 is used to emit light source light, and the light source light may include a single band or multiple different bands. The light source device 301 may be a single light source or may include multiple light sources, and the light source may be a laser light source, an LED light source, or a fluorescent light source, etc. Further, the light source may be a single light emitting element or a light emitting element array, and the light emitting element array may include light emitting elements of different colors. For example, the light source is a multicolor laser, and the light source is a light emitting element array including multiple lasers, such as the light source may include a blue laser and a red laser, or include a blue laser and a green laser, or include a blue laser, a red laser, and a green laser at the same time.

[0052] Optionally, the light source includes a light source unit, which includes a substrate and a plurality of light-emitting elements. The substrate has a quadrilateral shape, such as a roughly square or roughly rectangular shape, when viewed from above. The substrate has a mounting surface for mounting the light-emitting elements, and the mounting surface is, for example, a flat surface. In addition, a heat dissipation component such as a heat sink may be provided on the surface opposite to the mounting surface of the substrate. The substrate is formed of a material with high heat dissipation properties, such as a metal material. The plurality of light-emitting elements are arranged in an array relative to the mounting surface of the substrate. The light-emitting element is a laser light source having an emitting surface for emitting laser light; it may also be an LED light source. The light source may be a single red, green, and blue LED light source, an LED light source array, or a COB light source; it may also be a blue LED light source and a yellow light source.

[0053] The meta-lens 302 may also be called a metalenses, which is made of an optical element that focuses light on a metasurface. The metasurface mainly refers to a two-dimensional metamaterial composed of nanostructures with an ultra-thin thickness. The nanostructures that make up the metasurface may be structures such as holes, slits, or protrusions. The following further describes the meta-lens 302 by taking the nanostructure of the metasurface as a nanocolumn as an example.

[0054] like Figure 4 As shown, the meta-lens 302 includes a substrate 21 and a plurality of nano-pillars 22, and the substrate 21 and the plurality of nano-pillars 22 are formed of a material having a high transmittance for the wavelength band of the light beam. If the wavelength of the light beam is in the visible wavelength region, for example, 445 nm, the materials of the substrate 21 and the plurality of nano-pillars 22 may include, for example, optical glass, silicon oxide (SiO2), titanium oxide (TiO2), etc. The substrate 21 and the nano-pillars 22 may be formed integrally with each other, or may be formed independently, and joined when arranged in the X direction and the Y direction. The plurality of nano-pillars 22 are arranged on the surface of the substrate 21 at intervals d. That is, the widths t and w of the nano-pillars adjacent to each other on the XY plane may be the same size or different sizes. The nano-pillars are adjusted to realize the change of the light transmission phase from 0-2, and these nano-pillars are arranged in a corresponding manner to form a meta-lens to realize the focusing function, and the light focusing is realized by the phase obtained by the different rotation angles of the nano-pillars.

[0055] The liquid crystal panel 303 is used to modulate the light source to form modulated light. Each pixel unit of the liquid crystal panel 303 may include one or more pixel sub-units, and different pixel sub-units are used to process light of different wavelengths. For example, Figure 4As shown, the liquid crystal panel 303 includes a red pixel subunit 31, a green pixel subunit 32, and a blue pixel subunit 33, wherein the red pixel subunit 31 is used to process red light, the green pixel subunit 32 is used to process green light, and the blue pixel subunit 33 is used to process blue light. Further, the size of each pixel subunit in the pixel unit of the liquid crystal panel 303 is the same, such as the size of the red pixel subunit 31, the green pixel subunit 32, and the blue pixel subunit 33 are the same.

[0056] The meta-lens 302 guides the red light emitted by the light source device 301 to the red pixel unit 31, guides the green light emitted by the light source device 301 to the green pixel unit 32, and guides the blue light emitted by the light source device 301 to the blue pixel unit 33. The meta-lens 302 has the function of focusing light of different wavelengths at different positions. Corresponding to the position of the pixel sub-unit of the pixel unit in the liquid crystal panel 303, the meta-lens 302 satisfies:

[0057] If the incident light includes three wavelengths of light, λ1<λ2<λ3, then

[0058] w(x1, λ1)=w(x2, λ2)+k1π=w(x3, λ3)+k2π

[0059] The rotation angle of the nanorods of the metalens 302 satisfies:

[0060]

[0061] in, represents the rotation angle, xi represents the coordinate of the first direction of the focus of the incident wavelength λi in the focus coordinate system, k1 is an integer constant, d represents the distance between the meta-lens and the first liquid crystal element, and (x, y) represents the coordinate of the nanostructure in the nanostructure coordinate system. k1 and k2 satisfy that the phase difference corresponding to the three wavelengths is 0 or an integer multiple of 2π; the sum of the distances of the three focal points is equal to the pixel subunit height of the liquid crystal panel. (xi, yi) represents the coordinate of the focus coordinate system, xi represents the first direction, and yi represents the second direction. The above two wavelengths of light satisfy that the focus position falls on a position where the first direction is different from the second direction, that is, it falls on a position where the longitudinal position is the same but the lateral position is different in the focus coordinate system.

[0062] Figure 5 A schematic diagram of the structure of a projection device provided by an embodiment of the present invention. Figure 5 As shown, the projection device includes a light source device 301, a polarization adjustment element 306, a meta-lens 302, a liquid crystal panel 303 and a projection lens 304. Figure 3 The embodiment shown is different in that Figure 5The projection device shown also includes a polarization adjustment element 306, which is used to adjust the polarization direction of the light source light emitted by the light source device 301, so that different lights in the light source light have different polarization directions. For example, if the light source light includes a first light and a second light, the polarization adjustment element 306 is used to make the first light have a first polarization direction, and the second light have a second polarization direction, wherein the polarization directions of the first polarization direction and the second polarization direction are different. For example, if the light source light includes a first light, a second light and a third light, the polarization adjustment element 306 is used to make the first light have a first polarization direction, the second light have a second polarization direction, and the third light have a third polarization direction, wherein the polarization directions of the first polarization direction, the second polarization direction and the third polarization direction are different.

[0063] The meta-lens 302 has the function of focusing light with different polarization directions at different positions. Corresponding to the position of the pixel sub-unit of the pixel unit in the liquid crystal panel 303, the polarization angle of the light incident on the meta-lens 302 satisfies:

[0064]

[0065] in, represents the polarization angle, λi represents the wavelength of the incident light, d represents the distance between the meta-lens and the liquid crystal panel, and Δr represents the center distance between adjacent pixel sub-units of each pixel unit in the liquid crystal panel.

[0066] Continue reading Figure 5 The projection device may further include a polarization control device 305 located between the light source device 301 and the polarization adjustment element 306. The polarization control device 305 is used to control the polarization direction of the light source light emitted by the light source device 301, so that the polarization directions of all lights in the light source light are consistent, which is beneficial to the adjustment of the polarization adjustment element 306.

[0067] For example, the polarization adjustment element 306 includes three regions, each region makes the incident light and the outgoing light deflect at different angles, such as 45 degrees, 90 degrees, 20 degrees, etc. The light source device 301 generates the first light, the second light and the third light in sequence, and the polarization directions of the first light, the second light and the third light incident on the polarization adjustment element 306 are consistent. The three regions of the polarization adjustment element 306 are located on the light path in sequence, so that the polarization angles of the first light, the second light and the third light are deflected by 45 degrees, 90 degrees and 20 degrees respectively, so that the polarization directions of the first light, the second light and the third light incident on the meta-lens 302 are different, and the meta-lens 302 guides the first light, the second light and the third light to the first pixel sub-unit, the second pixel sub-unit and the third pixel sub-unit of the liquid crystal panel 303 respectively. Figure 5 Accordingly, the liquid crystal panel 303 displays the color field images of the first light, the second light and the third light of the input signal in time sequence.

[0068] Since the meta-lens 302 can guide light of different colors to the corresponding pixel sub-units on the first liquid crystal element 4, the liquid crystal panel 303 can be a black and white screen to avoid light loss caused by the color filter element.

[0069] In some embodiments, the projection device may also include multiple liquid crystal panels. The following takes a transmissive meta-lens and a 2LCD projection device as examples to further illustrate the embodiments of the present invention. It should be understood that the projection device of the embodiment of the present invention may also be a 3LCD or 2LCOS or 3LCOS projection device, etc., and the meta-lens may be a transmissive meta-lens or a reflective meta-lens.

[0070] Figure 6 FIG. 1 is a schematic diagram of another projection device provided by an embodiment of the present invention. Figure 6 As shown, the projection device includes a first light source 1, a first meta-lens 3, a first LCD screen 4, a second light source 7, a second meta-lens 9, a second LCD screen 10, a light combining element 5 and a projection lens 6. The light source light emitted by the first light source 1 is guided to the first LCD screen 4 through the first meta-lens 3, and is modulated at the first LCD screen 4 to form a first modulated light; the light source light emitted by the second light source 7 is guided to the second LCD screen 10 through the second meta-lens 9, and is modulated at the second LCD screen 10 to form a second modulated light. The first modulated light and the second modulated light are combined by the light combining element 5 and incident on the projection lens 6.

[0071] The light source light emitted by the first light source 1 includes at least two lights of different wavelength bands, such as red light and green light, or blue light and green light, or blue light and yellow light, or lights of three colors, namely, red light, green light and blue light. Figure 6 As shown, the light source light emitted by the first light source 1 includes red light, green light and blue light, and the first meta-lens 3 guides the red light to the red pixel unit of the first LCD screen 4, guides the green light to the green pixel unit of the first LCD screen 4, and guides the blue light to the blue pixel unit of the first LCD screen 4. In this embodiment, the color filter element can be omitted in the first LCD screen 4 to avoid light loss caused by the color filter element.

[0072] The light source emitted by the second light source 7 may include only light of a single wavelength band, or may include light of multiple different wavelength bands. If it includes only light of a single wavelength band, the projection device may not include the second meta-lens 9, and the second LCD screen 10 may be a monochrome screen or a black and white screen. For example, the light source emitted by the first light source 1 includes red light, green light, and blue light, and the light source emitted by the second light source 7 is green light, which improves the projection brightness. Figure 6The light source light emitted by the second light source 7 includes red light, green light and blue light. The second meta-lens 9 guides the red light to the red pixel unit of the second LCD screen 10, guides the green light to the green pixel unit of the second LCD screen 10, and guides the blue light to the blue pixel unit of the second LCD screen 10.

[0073] Each pixel in the first LCD screen 4 includes at least two sub-pixels (that is, two or three sub-pixels). For example, if the light source light emitted by the first light source 1 includes red light and green light, then each pixel in the first LCD screen 4 includes a red sub-pixel and a green sub-pixel. For another example, if the light source light emitted by the first light source 1 includes red light, green light and blue light, then each pixel in the first LCD screen 4 includes a red sub-pixel, a green sub-pixel and a blue sub-pixel.

[0074] Each pixel in the second LCD screen 10 includes at least one sub-pixel (that is, one, two or three sub-pixels). For example, if the light source light emitted by the second light source 7 includes only blue light, then each pixel in the second LCD screen 10 includes only blue sub-pixels. For example, if the light source light emitted by the second light source 7 includes blue light and green light, then each pixel in the second LCD screen 10 includes a blue sub-pixel and a green sub-pixel. For example, if the light source light emitted by the second light source 7 includes red light, green light and blue light, then each pixel in the second LCD screen 10 includes a red sub-pixel, a green sub-pixel and a blue sub-pixel. In this embodiment, the size of the pixels of the first LCD screen 4 and the size of the pixels of the second LCD screen 10 are the same. For example, if each pixel in the first LCD screen 4 includes two sub-pixels and each pixel in the second LCD screen 10 includes one sub-pixel, the width and / or height of the two sub-pixels in the pixel of the first LCD screen 4 is equal to the width and / or height of the one sub-pixel in the pixel of the second LCD screen 10; if each pixel in the first LCD screen 4 includes three sub-pixels and each pixel in the second LCD screen 10 includes two sub-pixels, the width and / or height of the three sub-pixels in the pixel of the first LCD screen 4 is equal to the width and / or height of the two sub-pixels in the pixel of the second LCD screen 10. It should be understood that in some other embodiments, each pixel in each LCD screen of the 2LCD projection device may include 1-3 sub-pixels. Similarly, each pixel in each LCD screen of the 3LCD projection device may include 1-3 sub-pixels, and the pixel sizes of each LCD screen are the same.

[0075] The following is an example of a timing control method:

[0076] The first projection sequence passes through the first LCD screen 4, including the first sub-sequence, the second sub-sequence and the third sub-sequence. The first sub-sequence lights up the blue light source, and the light passing through the first meta-lens 4 is incident on the blue sub-pixel of the first LCD screen 4. The second sub-sequence lights up the green light source, and the light passing through the first meta-lens 4 is incident on the green sub-pixel of the first LCD screen 4. The third sub-sequence lights up the red light source, and the light passing through the first meta-lens 4 is incident on the red sub-pixel of the first LCD screen 4; the second projection sequence passes through the second LCD screen 10, and is lit like the first projection sequence, and the first projection sequence and the second projection sequence are simultaneously or separated by an allowed time; the brightness is enhanced by emitting twice the light within the timing range, and the color filter element is omitted at the same time, thereby avoiding the light loss caused by the color filter element.

[0077] In a 2LCD projection device, the original image can be divided into a first pixel image and a second pixel image, represented as Image1 and Image2; wherein Image1 is input to the first LCD screen 4, and Image2 is input to the second LCD screen 10; the scanning driver 1 of the first LCD screen 4 starts to control the polarization splitting characteristics of the liquid crystal molecules line by line according to the image data of the first LCD screen 4; the scanning driver 2 of the second LCD screen 10 starts to control the polarization splitting characteristics of the liquid crystal molecules line by line according to the image data of the second LCD screen 10; the scanning time of the two LCDs is almost equal or the time difference is less than the preset value; after the scanning driver 1 / 2 has completed the scanning, a reset is performed according to Vblank.

[0078] In some other embodiments, the light source light emitted by the first light source 1 includes light of two bands, and the light source light emitted by the second light source 7 also includes light of two bands, and the light source light emitted by the first light source 1 and the light source light emitted by the second light source 7 can be synthesized into white light, and the light source light emitted by the two light sources includes light of the same band, thereby enhancing the light of the band. For example, the light source light emitted by the first light source 1 includes red light and green light, and the light source light emitted by the second light source 7 includes blue light and green light. Since the light source light emitted by the two light sources both include green light, the projection brightness can be improved.

[0079] Optionally, the first LCD screen 4 and the second LCD screen 10 can achieve a difference in the first displacement value in the physical space. Specifically, the first LCD screen 4 is located at the first position, and the second LCD screen 10 is located at the second position, so that the pixels in the projection picture formed by the first modulated light emitted by the first LCD screen 4 and the corresponding pixels in the projection picture formed by the second modulated light emitted by the second LCD screen 10 deviate from the preset distance, such as the pixels in the projection picture formed by the first modulated light and the pixels in the projection picture formed by the second modulated light can deviate from the spacing of half a pixel in the row direction and the column direction, thereby achieving pixel expansion.

[0080] Further, see Figure 6, the first light source 1 and the second light source 7 may be provided with a first shaping lens 2 and a second shaping lens 8 on their light output sides, respectively. Each light emitted from the light source portion is incident on the shaping lens. The shaping lens may have a plurality of collimating lenses. The collimating lenses and the light emitting elements may correspond to each other in a one-to-one manner. Therefore, the light emitted from each light emitting element is converted into parallel light by the corresponding collimating lens. Alternatively, the shaping lens includes a focusing lens to reduce the light beam; or the shaping lens includes a microlens array to make the light beam uniform and parallel.

[0081] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A projection device, characterized in that: include: A light source device, for generating light source light, wherein the light source light includes a first light and a second light; A first liquid crystal panel, used for modulating the light from the light source, wherein each pixel unit of the first liquid crystal panel includes a first pixel sub-unit and a second pixel sub-unit, wherein the first pixel sub-unit is used for processing the first light, and the second pixel sub-unit is used for processing the second light; a polarization adjustment element, located at the light output side of the light source device, and used to adjust the polarization direction of the light source light so that the first light has a first polarization direction and the second light has a second polarization direction, wherein the first polarization direction and the second polarization direction are different; The meta-lens is located between the polarization adjustment element and the first liquid crystal panel, and is used to guide the first light to be incident on a first pixel subunit of the first liquid crystal panel, and guide the second light to be incident on a second pixel subunit of the first liquid crystal panel.

2. A projection device according to claim 1, characterized in that: The light source light also includes a third light; Each pixel unit of the first liquid crystal panel further includes a third pixel sub-unit, and the third pixel sub-unit is used to process the third light; The polarization adjustment element is further used to make the third light have a third polarization direction, and the third polarization direction is different from the polarization directions of the first polarization direction and the second polarization direction; The meta-lens is further used to guide the third light to be incident on a third pixel subunit of the first liquid crystal panel.

3. A projection device according to claim 1, characterized in that: The light source light further includes a fourth light, and the projection device further includes: A second liquid crystal panel, each pixel unit of the second liquid crystal panel includes a fourth pixel sub-unit, and the fourth pixel sub-unit is used to process the fourth light.

4. A projection device according to claim 1, characterized in that: The polarization angle of the light incident on the metalens satisfies the following conditions: in, represents the polarization angle, λi represents the wavelength of the incident light, d represents the distance between the meta-lens and the first liquid crystal panel, and Δr represents the center distance between adjacent pixel sub-units of each pixel unit in the first liquid crystal panel.

5. The projection device according to claim 1, characterized in that: Also includes: The polarization control device is located between the light source device and the polarization adjustment element, and is used to control the polarization direction of the light from the light source so that the polarization directions of all lights in the light from the light source are consistent.

6. A projection device according to claim 2, characterized in that: The light source device generates the first light, the second light and the third light in a time sequence.

7. A projection device according to claim 2, characterized in that: The first liquid crystal panel displays color field images of first light, second light and third light of an input signal in time sequence.

8. The projection device according to claim 1, characterized in that: The first liquid crystal panel is a black and white screen.

9. The projection device according to claim 1, characterized in that: The first pixel sub-unit and the second pixel sub-unit have the same size.

10. The projection device according to claim 2, characterized in that: The first pixel sub-unit, the second pixel sub-unit and the third pixel sub-unit have the same size.

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